While it strays a bit from the ambient side, I think it was a beautiful track. You're definitely skilled at writing for piano (or improvising if that's what you did). Though, I couldn't really see how the theme was represented. While it works with your story, the goal of the jam wasn't to build your own story, but to picture the painting and theme.
Loved the contrast between the 2 sections, though I don't think that choir was necessary.
Besides that I do have to give good points in the composition, mixing and listenability categories because of the sheer quality of the track. Great job !